Roy T. Fielding writes:
...
>
> I guess that the best thing to include is a paragraph saying
>
> A proxy may encode portions of the Request-URI prior to forwarding
^^^
> the message if and only if such encoding is necessary to make the
^^^^^^^^^^^^^^
> message compliant with HTTP.
This language doesn't really go together. "If and only if" implies
necessity, at least to any mathematically oriented readers,
so it ought to be "must", not "may", or else you should
get rid of the "if" part.
--Shel